Method of making belts



Dec. 7, 1943.

A. L. FREEDLANDER METHOD OF MAKING BELTS Original Filed April 29, 1940INVENTOR AIM/MM L. Minn/VOL! 7 a MAL ATTORNEYS Patented Dec. 7, 1943METHOD OF MAKING BELTS Abraham L. Freedlander, Dayton, Ohio, asslgnor toThe Dayton ,Rubber Manufacturing Company, Dayton, Ohio, a corporation ofOhio Original application April 29, 1940, Serial No. 332,225. Dividedand this application August 13, 1941, Serial No. 406,638

1 Claim. (01. 154-1) in the belt of harmful internal stresses or de-"structive strains. a

It is a further object of this invention to provide a V-belt of suchconstruction that the neutral axis thereof is disclosed adjacent theouter side thereof, and wherein the compression section comprises fiberreinforced rubber and is provided with teeth formed therein andextending only partially therethrough from the inner or lower sidethereof in such manner that the I fiber reinforced rubber above theintersticesbetween the teeth provides a resilient connection I betweenthe teeth of the compression section.

'These and other objects and advantages will appear from the followingdescription taken in connection with the drawing.

In the drawing:

Figure 1 is a perspective cut-away sectional view in perspective of animproved belt made in accordance with this invention;

Figure 2 is'a view similar to Figure 1 illustrating a belt of slightlydifferent construction;

Figure 3 is a cross-sectional view taken through a belt constructed asshown in Figure 1;

Figure 4 is a similar cross-sectional view of a belt constructed asillustrated in Figure 2;

Figures 5 and 6 are cross-sectional views of the belt structuresillustrated in Figures 2'and 3 respectively taken on a plane extendingthrough a portion cut out to form the teeth.

The body of the belt of the present invention is preferably made bywinding a layer of rubber composition reinforced with fine textilefibers herein illustrated comprises the compression section I formed ofrubber, reinforced with fine par allel textile fibers disposedtransversely therein, upon which is superposed the strength band or izedbias-laid square woven fabric.

strength sectionl, which is formed of a plurality of plies of rubberizedstraight-laid square woven textile fabric secured together in graduatedtension. As a modification, the compression section I may comprise asection 3 formed of one or more plies of rubberized bias-laid squarewoven textile fabric as shown in Figure 2.

In order to strengthen the teeth formed in the compression section I,the lower surfaces thereof are provided with a cover 4 formed of rubber-The tooth covering 4 is preferably secured to the compression section Iafter the teeth are cut therein and, in cutting the teeth, it ispreferable that, as

shown, the interstices between adjacent teeth terminate at a substantialdistance below the up, per surface of the compression section I in orderthat a portion of the material of the compression section I shouldextend from tooth to tooth and thus form a reinforcing and cushioningsection between the teeth.

Enclosing the sides of the belt is the inner cover member 5 which isalso formed of bias-laid square woven rubberized fabric.

Disposed about the inner cover member 5 is the outer cover member 8which is also formed of bias-laid rubberized square woven textile fabricand the cover layers 5 and 6 are overlapped at the outer-or upper sideof .the belt, as shown at 6a, 6b in order to fully protect the belt andstrengthen the cover thereof.

While the tooth covering t has been decignated as comprising a singleply, it is, of course, to be understood that it may comprise a greaternumber of plies secured together to provide additional strength to theinner tooth surfaces where such additional strength is necessary ordesirable. It is likewise to be understood that the section 3 maycomprise either one ply or any The presence of these fibers in thematerial substantially decreases the impact of the side ol. therespective belt teeth upon the driving pulley, because, while theyieldabiiity or the material is not appreciably changed, neverthelessthe elasticity or "bounce" of the fiber impregnated rubber issubstantially less than that of rubber unprovided with suchreinforcement. The; reinforcement thus substantially increasesthe-lateral incompressibility of the compression section I, while "alsodecreasing the bounce or'impact of the teeth upon a driving pulleywithout, in any way, decreasing, but on r the contrary, in someinstances, increasing the flexibility or bendabiiity of the compressionsec- .tween parts in tension and parts in compression.

In forming the section 2, the piles of straight laid square wovenrubberized fabric are preferably wound upon one another at graduatedtension, i. e., the lower or -'inner plies will have greater tensionthan the outer plies and the tension of the respective plies decreasesprogressively from the inner or lower ply to the outer or upper ply.

Due to this graduated tension of the plies of the strength section I,this section normally tends to draw the helt'into circular form, and, asthe strength band or section 2 is, in eflect, the backbone of the beltand adapted to supply the greater portion of the tensile strengththereof, this graduated tension in the strength section 2 materiallyaids the belt in conforming to acutely arcuate surfaces of grooveddriving pulleys of small diameter. 1

The term straight-laid" indicates that the threads of the square wovenfabric of the section 2, which extend in one'direction are disposedsubstantially parallel to the longitudinal axis of the belt, while theother threads which are substantially perpendicular thereto are disposedtransversely of the belt.

The transversely disposed threads serve to aid the bending of thestrength section 2, in operation of the belt, while the longitudinallydisposed threads impart substantial tensile strength to the strengthband or section 2. The tooth covering 4 and the section 3 are formed, asabove described, of bias-laid square woven rubberized textile fabric andthe term bias-laid indicates that the threads, as illustrated, are alldisposed diagonally with respect both to the longitudinal and transverseaxes of the material and the belt.

The provision of two-, ply covering of the side or driving surfaces ofthe belt by the inner cover member 5 and outer cover member 6 maintainsthe noise of the belt in operation at a minimum value.

The full overlapping of the outer cover member lalso provides a flat.continuous outer surface for the belt. As is seen particularly inFigures 1 and 2, the termination of the interstices between the teeth ata substantial distance below the upper surface of the compressionsection i provides a substantial resilient connecting body betweenadjacent teeth.

The teeth are out after the sections of the belt body, including theinner and outer cover members of the wrapper,.have been assembled andbefore the built-up structure is placed in the mould for vulcanization.In this case, after the teeth have been cut out of the compressionsection I, and through the inner and outer cover members of the beltwrapper, the teeth covering layer 4 isapplied over and in between theteeth as shown in Figures 1 and 2. Thereafter, the assembled structureis placed in a mould and subiected to heat and pressure to vulcanize allthe belt sections into one complete integral unit or body.

In the belt construction illustrated in Figure 2, the Stiilex isprovided with a fabric section 3 to increase the tensile strength of thecompression section.

It will be understood that the above described vstructure is merelyillustrative of the manner in which the principles of my invention maybeutilized and that I desire to comprehend within my invention suchmodifications as come within the scope of the claim and the invention.

. Having thus fully described my invention, what I claim as new anddesire to secure by Letters Patent is:

An improved method of making V-belts comsistlng of biased-laid squarewoven rubberized i fabric, cutting teeth along the inner side surface ofthe belt, laying a covering member of rubberized fabric over and inbetween the teeth, said teeth covering member extending as a continu=ous web longitudinally of the inner surface, and vulcanizing the thusformed belt to unite the laminated layers into an integral unitary belt.

' ABRAHAM L. FREEDLANDER.

